PLANNING AND ENVIRONMENT DEPARTMENT
ENVIRONMENT DIVISION
Dispensations for water quality parameters granted under Article 13(1) of the Water (Jersey) Law 1972 as Amended
(Public)
Purpose of the Report
The Minister for Planning and Environment (The Minister) is requested to:
- Grant the renewal of the existing dispensations of water quality parameters for the period 01 January 2009 to 31 December 2013.
- Approve the scheme for monitoring of the dispensation parameters provided with the application under Article 13(1)(b) of the Water (Jersey) Law 1972 as Amended (the Law).
Background
Under Article 12(1) of the Law as Amended, The Jersey New Waterworks Company Limited (Jersey Water) may in writing apply for a dispensation from the requirements of paragraph 2 of the Schedule of the Law subject to a number of conditions including:
- that the dispensation is necessary to maintain a supply of water for domestic purposes;
- that a supply of water for those purposes cannot be maintained in the specified areas by any other reasonably practicable means; and
- that the supply of water in accordance with the dispensation does not constitute a potential danger to human health.
Applications for dispensations from Jersey Water for nitrate (and nitrite), manganese and iron and details of the proposed monitoring scheme were received, in writing, by The Minister on 11 April 2008.
The request for dispensations is identical to that granted by the then Environment and Public Services Committee for the period 1 January 2004 to 31 December 2008.
Under Article 13(1) of the Law as Amended, The Minister may grant an application for dispensation if, but only if, the Minister is satisfied that each of the conditions detailed above is established and the Minister approves the monitoring scheme provided with the application by Jersey Water (Annex 1).
Under Article 19(1) of the Law as Amended, where any human health or public health related issues arise in relation to applications for dispensations, The Minister is required to consult with The Minister for Health and Social Services. This consultation has been undertaken (Decision Reference: MD-HSS-2008-0049).
Discussion
The current dispensation levels have been in place since 1 January 2004 (the date of enactment of the Law Amendments). The dispensations, for the whole Island, are for nitrate (and nitrite), iron and manganese and are set out in Table 1.
Table 1 Current (and proposed) levels of dispensation
Parameter | Maximum allowable concentration | Percentage of samples allowed per annum (%) |
Nitrate (and nitrite) | 70 mgl-1 | 33 |
Manganese | 100 µgl-1 | 5 |
Iron | 500 µgl-1 | 5 |
Jersey Water is mainly reliant on the collection and storage of surface water and thus does not have the possibility of blending surface and sub-surface waters to reduce the concentration of these parameters.
Jersey Water has instigated various measures to reduce the concentration of these parameters, including:
1.1 Nitrate (and nitrite)
- Introduction of online monitoring at water resource sites over the past five years to enable blending of source water at critical times.
- Mixing nitrate free water from the desalination plant to dilute surface water source nitrate levels.
Considerations
Levels of nitrates in source water in the Island are related to rainfall. Recent wet summers have caused increased run-off from agricultural land with stream sources frequently being greater than 50 mgl-1 (the maximum allowable concentration). In such circumstances, it is impossible to blend surface waters, so that the water in supply does not exceed 50mgl-1 for nitrate.
1.2 Manganese
- Oxidation of raw water at the treatment works and removal by rapid gravity filters.
- Blending of raw waters prior to treatment.
Considerations
Manganese is mainly derived from the biological breakdown of vegetation in reservoirs during spring and autumn caused by rapid temperature inversion. Gravity filters cannot cope with this sudden shock loading and short-term peaks in manganese may occur.
1.3 Iron
- Rolling programme to replace old iron and steel service pipes at a rate of 2.5 km length per year.
Considerations
Routine maintenance and removal of pipes disturbs iron deposits and can result in short-term peaks.
- Health implication
As required under Article 19(1), The Minister has consulted on the human or public health related issues arising from the dispensations with the Minister for Health and Social Services (Decision Reference: MD-HSS-2008-0049).
The provisional health-based guideline value for manganese set by the World Health Organisation is 500 µgl-1 (i.e. more than the stipulated 100 µgl-1 requested in the dispensation). No health-based guideline value exists for iron.
Nitrate therefore represents the major exceedence of a health-based guideline value. It is recognised that Jersey Water is unable to control the cause of nitrate in its source water and that subsequent interventions to reduce concentrations are limited.
- Long-term solutions
Long-term solutions for reducing nitrate in source water, through better land management and use, may be achieved through the implementation of Water Catchment Management Areas under Article 14 of the Water Pollution (Jersey) Law 2000 and the EU Water Framework Directive (EU 2000/60/EC).
Implementation on a pilot scale is about to commence in the Val de la Mare catchment. The work is being led by Environmental Protection, Planning and Environment Department and will be undertaken alongside the work of the Countryside Renewal Scheme operated by the Planning and Environment Department.
The terms of reference for the pilot phase project for the Val de la Mare catchment are to:
1) Assess the impact on water quality that a series of identified changes in land management and use can achieve.
2) Investigate the practicalities and costs of undertaking such changes.
3) Develop knowledge and working relationships necessary for island-wide implementation.
This work will complement the ongoing implementation of the Water Pollution (Jersey) Law 2000.
Recommendation
The Minister:
- Grants dispensations for water quality parameters to Jersey Water under Article 13(1) of the Law as Amended as set out in this report for the period 01 January 2009 to 31 December 2013.
- Approves the scheme for monitoring of the dispensation parameters provided with the application (Annex 1) under Article 13(1)(b) of the 1972 Law as Amended.
Written by: Dr Tim du Feu, Head of Water Resources - Environmental Protection
Approved by: Mr Chris Newton, Director, Environment Division
Ministerial Decision ref: MD-PE-2008-0248
11 November 2008
Annex 1. Proposed Regulatory Monitoring Scheme
for the Year 2009
Water Supply Zones
The sampling frequencies set out in The Water Supply (Water Quality) Regulations 2000 (England and Wales) are based on the population size of the zone. The estimated population of the Island is 90,800 (as at Dec. 2007) and the Company supplies approximately 90%; therefore the population supplied is approximately 81,500.
For the purposes of setting the sampling frequencies, the population size will be taken as 100,000 and the Island taken as one supply zone.
Table 2 in Schedule 3 of the Regulations sets out the frequency of sampling the water supply zones as listed below. The proposed sampling frequency is highlighted in bold.
Table 2
Check monitoring |
Parameter | Population size | Reduced | Standard |
Iron | 80,000-100,000 | 38 | 76 |
Manganese |
Nitrate (and nitrite) |
Table 2 (cont’d)
Audit monitoring |
Parameter | Population size | Reduced | Standard |
Iron | 5,000-100,000 | | 8 |
Manganese |
Nitrate (and nitrite) |
As the water Jersey Water uses originates from, or is influenced by, surface waters, the sampling frequency for iron and manganese will be at the check monitoring frequency.
The Company uses the chloramination disinfection process, therefore the sampling frequency for nitrate and nitrite will be at the check monitoring frequency.
gov.je